What is the value of the following logarithm? $\log_{81} 3$
If $b^y = x$ , then $\log_{b} x = y$ Notice that $3$ is the fourth root of $81$ That is, $\sqrt[4]{81} = 81^{1/4} = 3$ Thus, $\log_{81} 3 = \dfrac{1}{4}$.